Rapid fire is a group of features that includes Turbo and Toggle functionality. Those are paid features that become available after you purchase Rapid Fire feature, or enable its trial period.
Turbo is the feature that permits to fire the mapped key or sequence repetitively with the adjustable pause between shots.
Toggle is the feature that allows to imitating the pressed key: you press the button once and the key goes down, you press it once more and the key goes up.
It’s important to know some nuances:
Both these features are not available for Hold until release mode, they work only for Execute at once.
When you assign a controller button Turbo, you need to unmap the button too. Otherwise, reWASD will recognize the pressed and held button input, and Turbo with pauses will not work.
If you add a Toggle button inside the Shift modifier, you’ll need to go back to Shift modifier to turn it off. Same with Shortcuts: if you add a Toggle mapping to a shortcut, you’ll need to press the Shortcut again to turn it off.